fix(member): add error handling and toast feedback for missing user profiles

app/(app)/member/[id]/page.tsx

@@ -1,38 +1,40 @@
 /**
  * @file member/[id]/page.tsx
- * @description Server component rendering the detailed profile page for a specific member by fetching their user profile data.
+ * @description Server component rendering the detailed profile page for a specific member by validating the ID format and fetching user profile data.
  */
 
 import { UserService } from "@/services/user.service";
-import { notFound } from "next/navigation";
+import { redirect } from "next/navigation";
 import MemberHeader from "../MemberHeader";
 import MemberProfileCard from "./MemberProfileCard";
 
 /**
- * Properties for the MemberDetailPage component.
- *
- * @interface MemberDetailPageProps
- * @property {Promise<{ id: string }>} params - Promise containing route context parameters with the target member ID.
- */
-interface MemberDetailPageProps {
-  params: Promise<{ id: string }>;
-}
-
-/**
- * Renders the member detail page by resolving the route parameter, fetching the user profile by ID,
- * and displaying their header and profile card or triggering a 404 page if the member is not found.
+ * Renders the member detail page by resolving route parameters, validating the member ID syntax,
+ * fetching profile data, and displaying the header and profile card or redirecting with an error parameter if not found.
  *
  * @async
- * @param {MemberDetailPageProps} props - The component props.
+ * @param {Object} props - The component props.
+ * @param {Promise<{ id: string }>} props.params - Promise containing route context parameters with the target member ID.
  * @returns {Promise<JSX.Element>} The rendered member detail page component.
  */
 export default async function MemberDetailPage({
   params,
-}: MemberDetailPageProps) {
+}: {
+  params: Promise<{ id: string }>;
+}) {
   const { id } = await params;
+  const UUID_REGEX =
+    /^[0-9a-f]{8}-[0-9a-f]{4}-[4][0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/i;
+
+  if (!UUID_REGEX.test(id)) {
+    redirect("/member?error=member_not_found");
+  }
+
   const user = await UserService.findProfileById(id);
 
-  if (!user) notFound();
+  if (!user) {
+    redirect("/member?error=member_not_found");
+  }
 
   return (
     <div className="space-y-6 max-w-4xl mx-auto pb-12">

app/components/ui/ErrorToast.tsx

@@ -5,7 +5,7 @@
 
 "use client";
 
-import { useSearchParams, useRouter } from "next/navigation";
+import { useSearchParams, useRouter, usePathname } from "next/navigation";
 import { useEffect, useState, useRef, useCallback } from "react";
 import { AlertCircle, X } from "lucide-react";
 
@@ -19,6 +19,7 @@ const AUTO_DISMISS_TIME = 5000;
  */
 export default function ErrorToast() {
   const searchParams = useSearchParams();
+  const pathname = usePathname();
   const router = useRouter();
   const error = searchParams.get("error");
 
@@ -31,12 +32,19 @@ export default function ErrorToast() {
   const animFrameRef = useRef<number | null>(null);
 
   /**
-   * Dismisses the toast notification and cleans up URL parameters.
+   * Dismisses the toast notification and cleans up the URL error parameter while preserving the current pathname.
    */
   const dismissToast = useCallback(() => {
     setIsVisible(false);
-    router.replace("/dashboard", { scroll: false });
-  }, [router]);
+
+    // Clean up query parameters without forcing a hard redirect to dashboard
+    const params = new URLSearchParams(searchParams.toString());
+    params.delete("error");
+    const query = params.toString();
+    const newPath = query ? `${pathname}?${query}` : pathname;
+
+    router.replace(newPath, { scroll: false });
+  }, [router, pathname, searchParams]);
 
   // Show a toast message when an error occurs and reset the timer
   useEffect(() => {
@@ -90,12 +98,39 @@ export default function ErrorToast() {
 
   if (!isVisible || !error) return null;
 
-  const message =
-    error === "unauthorized_edit"
-      ? "You cannot edit tasks that belong to others or are in the trash."
-      : error === "task_not_found"
-        ? "The requested task does not exist or has been deleted."
-        : "An unexpected error occurred.";
+  /**
+   * Resolves the user-facing error title and detailed message based on the error query parameter.
+   *
+   * @returns {{ title: string; message: string }} An object containing the toast header title and body message.
+   */
+  const getErrorInfo = (): { title: string; message: string } => {
+    switch (error) {
+      case "unauthorized_edit":
+        return {
+          title: "Access Denied",
+          message:
+            "You cannot edit tasks that belong to others or are in the trash.",
+        };
+      case "task_not_found":
+        return {
+          title: "Task Not Found",
+          message: "The requested task does not exist or has been deleted.",
+        };
+      case "member_not_found":
+        return {
+          title: "Member Not Found",
+          message:
+            "The requested team member does not exist or has been removed.",
+        };
+      default:
+        return {
+          title: "Error",
+          message: "An unexpected error occurred.",
+        };
+    }
+  };
+
+  const { title, message } = getErrorInfo();
 
   return (
     <div
@@ -111,7 +146,7 @@ export default function ErrorToast() {
         <div className="flex flex-col flex-1">
           <div className="flex items-center justify-between">
             <h4 className="font-semibold tracking-wider uppercase text-destructive text-sm">
-              Access Denied
+              {title}
             </h4>
             <button
               onClick={dismissToast}